Merge branch 'linux-2.6'

1 files changed, 65 insertions, 0 deletions

diff --git a/arch/i386/kernel/verify_cpu.S b/arch/i386/kernel/verify_cpu.S
new file mode 100644
index 000000000000..e51a8695d54e
--- /dev/null
+++ b/arch/i386/kernel/verify_cpu.S
@@ -0,0 +1,65 @@
+/* Check if CPU has some minimum CPUID bits
+   This runs in 16bit mode so that the caller can still use the BIOS
+   to output errors on the screen */
+#include <asm/cpufeature.h>
+
+verify_cpu:
+	pushfl				# Save caller passed flags
+	pushl	$0			# Kill any dangerous flags
+	popfl
+
+#if CONFIG_X86_MINIMUM_CPU_MODEL >= 4
+	pushfl
+	orl	$(1<<18),(%esp)		# try setting AC
+	popfl
+	pushfl
+	popl    %eax
+	testl	$(1<<18),%eax
+	jz	bad
+#endif
+#if REQUIRED_MASK1 != 0
+	pushfl				# standard way to check for cpuid
+	popl	%eax
+	movl	%eax,%ebx
+	xorl	$0x200000,%eax
+	pushl	%eax
+	popfl
+	pushfl
+	popl	%eax
+	cmpl	%eax,%ebx
+	pushfl				# standard way to check for cpuid
+	popl	%eax
+	movl	%eax,%ebx
+	xorl	$0x200000,%eax
+	pushl	%eax
+	popfl
+	pushfl
+	popl	%eax
+	cmpl	%eax,%ebx
+	jz	bad			# REQUIRED_MASK1 != 0 requires CPUID
+
+	movl	$0x0,%eax		# See if cpuid 1 is implemented
+	cpuid
+	cmpl	$0x1,%eax
+	jb	bad			# no cpuid 1
+
+	movl    $0x1,%eax		# Does the cpu have what it takes
+	cpuid
+
+#if CONFIG_X86_MINIMUM_CPU_MODEL > 4
+#error	add proper model checking here
+#endif
+
+	andl	$REQUIRED_MASK1,%edx
+	xorl	$REQUIRED_MASK1,%edx
+	jnz	bad
+#endif /* REQUIRED_MASK1 */
+
+	popfl
+	xor	%eax,%eax
+	ret
+
+bad:
+	popfl
+	movl	$1,%eax
+	ret